Reflection gauge



Patented Nov. 22, i927.

,KUNITEDI,STATES PATENT, OFFICE.

wiLLIAM ints, orvonxnns, nnw yonx, assrenon'ro ELECTRICAL TESTING tanonaronrns, or NEW YORK, 15:. Y n CORPORATION OF NEW YORK.

REFLECTION GAUGE.

Applicationfiled August 20, 1924. Serial Ho. 733,105;

The invention relates to a gaugefor meas-. uring reflection factorsoffdilfusely reflect ing surfaces, and has for its objects to provide acheap and readily portable device having no moving parts,.which maybecarried in the vest pocket or in-a'pocket book,

and by means of which the reflection factors of surfaces may beobtainedwithout the use of test lamps or other illuminating devices. "1 d "tl bt '11 f ll .iese an 1m ler 0 180 s wi more u y appear inthe followinngspecification and accompanying drawings considered together orseparately.

The invention w11l be more thoroughly understood with the aid of thedescription given in connection with the accompanying drawings in whlchlike parts in all of the several figures are designated by correspondingcharacters of reference, and in which 7 Fig. 1 is a face view of thepreferred embodiment of the invention.

Fig. 2 is a section on the line 2-2 of Fig. 1, and

Fig. 3 is a face view of a slightlymodified form of the device.

Fig. 4 is a front view of'another modification of the invention.

In the preferred embodiment of the invention 3 designates a circularcard which may be of paper or any other suitable opaque material. Aroundthe disc, and at the pee riphery thereof, is printed, or otherwiseimpressed or delineated, an annular shaded wedge i which, starting fromthe point 5 with black is gradually and by almost im-V perceptibledegrees, shaded to merge into white at the same point, the wedge fromblack to white having made a circle.

lVithin the boundaries of the wedge the card is provided with a circularseries of perforations 6, preferably circular in form, and on the cardpreferably inside of the wedge and in circular series is arranged aseries of numbers 7 each designating an approximate reflection factor. vThe perforations may, if desired, instead of being in the shadedportion, be alongside of the same. j

In order to protect the face of the card, a disc 8 preferably oftransparent celluloid, is secured thereto. InFigs. 1 and 2 the disc 8 issecured in position by or hollow rivet 9. r V V r In Fig. 3 the wedge 10is straight and the sight openings 11 are arranged along the means of aneyeletwedge. The factor numbers 12 are arranged alongside 'of thejsame.The surface of the card bearing the wedge and numerals may be protectedby means of a transparent sheet, or the samemaybc treated-to a'coat oftransparent. varnish. I

In operation the gauge is placed over the reflecting surface, such as awall, ceiling, floor, etc, and the said surface is viewed through theopenings 6 or 1.1 as the case may be. WVhenthellight reflected from thesurface being tested through an opening corresponds in brightness withthat portion of the shaded wedge surrounding the opening, the factornumber at the opening will give the percentage of light reflected fromthe,

surface.

The operator must refrain from comparing the color ortint of the surfacewith that of the wedge, and deal with the brightness only. This'may befacilitated by observing the gauge and surface by twilight vision, thatis, by partly closing the eyes whereby color differences will not beapparent.

Some reflecting factors (approximate) are as follows:

. 5 Per cent. Blotting papern 7()75 Kraft wrapping paper 30-40 Wallpapers 10-70 White lead and oil paint"; 7 0 Light bufi' paint 65Whitebond paper y present.

In addition to its use as ameans for measuring reflection factors ofdiffusely reflecting surfaces, the device may also be employed inconnection with a photometer in which the light of the comparison lamp,or other source of illumination, iskept constant, the photometricbalance being; ob-

tained by varying the comparison surface,

thatis, varying reflection factor ofthe comparison surface, (the shadedjwedge).

this case the scale may be omitted when the reflection factor of thetest surface is known.

In accordance with the provisions of the patent statutes the principleof the invention has been described, together with the apparatus whichis now considered to represent the best embodiment thereof, but it isdesired to have it understood that the apparatus shown is merelyillustrative, and that the invention may be carried out in other ways.

The invention having been described, what is claimed as new and desiredto be secured by Letters Patent, is as follows:

1. In a reflection gauge, the combination-v with a body having a shadedsurface and a plurality of perforations 1n the shaded portion, of asequence of numbers representing reflection factors arranged relative tothe! p 2. In a reflection gauge, the combination with a body having anarea shaded in uninterrupted sequence from black to Whiteand pluralityof perforations extendingin a serieslengthwise through the. shadedportion, of a series of numbers associatedtherewith and designatingapproximately the light reflection factors of the shaded area.

3. In a reflection- -gauge, the combination with a body having an areashaded gradually from black to white and a pluralityof aperforationsextending lengthwise through the shaded portion, of a sequence ofnumbers arranged parallel tothe perforations :each in proximity to aperforation and designating approximately the light reflection factor ofthe shaded area surrounding the adjacent perforation.

This specification signed this eleventh day of August, 1924. r

' WILLIAM F. LITTLE;

